The purpose of this report was to describe the characteristics of patients transported by ambulance, in spite of being evaluated by the ambulance staff at the scene as not requiring prehospital care. A second aim was to compare these patients with those judged as being in need of this care. Three ambulance service districts located in different rural and metropolitan geographical areas were included in the study and all three were covered by a single emergency dispatch centre. Following the dispatch of ambulances, the staff assessed and recorded the medical needs of the patients at the scene, according to a questionnaire developed for the study. In addition to the questionnaire, data were extracted from the ambulance medical records database for each patient. If the patients were just transported by ambulance without receiving any other prehospital intervention, they were assessed as not being in need of the emergency service. The evaluation included events at the scene and during transportation. The ambulance staff making the needs assessments were emergency medical technicians and registered nurses. In this report, 604 patients who did not require prehospital care are described and compared with the remaining group of patients who required this care (1373). For analysis, descriptive statistics were used to analyse the data. The ambulance staff assessed that, among patients reported by the emergency medical dispatch centre as having abdominal or urinary problems, 42% did not need the ambulance service. Even among intrahospital transports (patients for whom medical personnel made the request for an ambulance), 45% did not require ambulance transport, as judged by the ambulance staff. Among patients reported by the emergency medical dispatch centre as having chest pain or other heart symptoms or trauma/accidents, respectively, only small percentages (18%) and (17%) did not require the ambulance service, as assessed by the ambulance staff. Most of the patients without obvious medical needs had been allocated an ambulance response for nonurgent conditions, that is priority level 2 or 3, but patients without medical needs were even found at the highest priority level 1. Of the patients who did not require an ambulance, more than half (55%) would have been able to get to a hospital in their own car or by taxi, whereas the remainder of the patients needed a transport vehicle in which they could lie down, but which was not equipped and staffed like an ambulance. Among the patients transported by the emergency medical service system in the study areas, a significant percentage were judged by the ambulance staff as not being in need of prehospital interventions. The majority were transported by a fully equipped emergency medical ambulance to an emergency medical department at a hospital, without requiring any prehospital interventions either at the scene or during transportation. The emergency medical service organization has to develop clear criteria for the utilization of ambulance services that can be accepted and implemented by the dispatch centres and by healthcare personnel. These criteria need to include safety margins and at the same time enable the appropriate use of resources.